Oral immune modulatory therapy using antigens bioencapsulated in plant cells

使用生物封装在植物细胞中的抗原进行口服免疫调节疗法

• 批准号: 8665459
• 负责人: HENRY DANIELL
• 金额: $ 41.66万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8665459
• 关键词: A-factor (Streptomyces); Acids; Address; Allergic; Allergic Reaction; Anaphylaxis; Animal Model; Antibodies; Antibody Formation; Antigen Presentation; Antigen-Presenting Cells; Antigens; Binding; Bioreactors; Blood Coagulation Factor; Bypass; Canis familiaris; Cell Wall; Cells; Chloroplasts; Clinical; Cold Chains; Complication; Development; Disease; Dose; Effectiveness; Encapsulated; Enzymes; Epithelial; Factor IX; Fermentation; Freeze Drying; Funding; Future; Gene Deletion; Generations; Genes; Genetically Modified Plants; Glycogen storage disease type II; Goals; Grant; Gut associated lymphoid tissue; Hemophilia A; Hemophilia B; Hemorrhage; Hereditary Disease; Human; IgE; Immune; Immune Tolerance; Immune system; Immunosuppression; Incidence; Inherited; Injection of therapeutic agent; Intravenous infusion procedures; Lettuce - dietary; Life; Ligands; Link; Lysosomal Storage Diseases; Mediating; Methods; Morbidity - disease rate; Mus; Nephrotic Syndrome; Nonsense Mutation; Oral; Patients; Pharmaceutical Preparations; Plants; Prevention; Production; Protein Deficiency; Proteins; Protocols documentation; Rare Diseases; Reagent; Recombinant Proteins; Regulation; Regulatory T-Lymphocyte; Replacement Therapy; Risk; Role; Sterility; Stomach; System; Terminator Codon; Testing; Therapeutic; Time; Tobacco; Transgenic Organisms; Transgenic Plants; Translations; United States National Institutes of Health; base; clinical application; commensal microbes; cost; cytokine; enzyme replacement therapy; experience; genetic manipulation; immunotoxicity; inhibitor/antagonist; microbial; mortality; novel; novel strategies; oral tolerance; prevent; prophylactic; receptor; response; standard care; therapeutic protein; tissue culture; translational study

DESCRIPTION (provided by applicant): Current treatment for many inherited protein deficiencies is based on intravenous infusion of recombinant proteins. The infused protein is expensive and is often encountered by antibody responses that neutralize therapy, thereby complicating treatment and further increasing costs. They also cause severe allergic or even life-threatening anaphylactic reactions. Oral immune modulatory therapy represents an ideal antigen-specific approach to prevent such responses because it is non-invasive and does not require immune suppression or genetic manipulation of the patient's cells. This proposal takes advantage of a unique concept based on the use of plant chloroplasts as highly efficient bioreactors for production and oral delivery of therapeutic protein antigens without a need for fermentation, purification, cold chain, or sterile injections. Bioencapsulated antigens are protected in the stomach from acids or enzymes, but are released in the gut when plant cell walls are digested by commensal bacteria. We propose to further advance this method for effective delivery of antigen-ligand fusions to the gut-associated lymphoid tissue. We have also made substantial progress towards development of an oral delivery system (based on the edible crop lettuce) suitable for clinical translation. In treatment of the X-linked bleeding disorder hemophilia, formation of inhibitory antibodies against the therapeutic clotting factor represents a serious complication that substantially increases morbidity and mortality. For example, patients with hemophilia B due to deletion or early stop codon in the factor IX (F.IX) gene are at increased risk for inhibitor formation. Not only are most F.IX inhibitors high-titer and difficult to eliminate, but these antibodies are often associated with potentially life-threatening anaphylactic reactions. Recently, we demonstrated that oral delivery of F.IX, produced by tobacco chloroplasts and bioencapsulated in plant cells, prevents formation of inhibitors and anaphylaxis in protein replacement therapy for hemophilia B (featured in PNAS 107:7101). These results illustrate the effectiveness of our approach towards immune modulatory therapy for inherited protein deficiencies. The goals of this proposal are to develop an oral immune modulatory protocol for hemophilia B that prevents or mitigates pathogenic antibody responses (including anaphylaxis); to dissect the underlying mechanisms of antigen presentation and immune regulation; to find alternative transmucosal carriers for effective antigen delivery; to test the approach for a different disease with similar antibody/anaphylactic response (the lysosomal storage disorder Pompe disease); to develop transplastomic lettuce to express F.IX for future oral delivery in humans; to investigate stability and microbial contamination of the freeze-dried transgenic material; and to perform translational studies in a large animal model of hemophilia B. We hypothesize that our low cost approach can be utilized in a prophylactic fashion in several diseases, such as hemophilia and lysosomal storage disorders, thereby eliminating the need for immune suppression.

描述（由申请人提供）：目前对许多遗传性蛋白质缺陷的治疗基于静脉输注重组蛋白质。输注的蛋白质价格昂贵，并且经常遇到抗体反应，从而中和治疗，从而使治疗复杂化并进一步增加成本。它们还会引起严重过敏甚至危及生命的过敏反应。口服免疫调节疗法是预防此类反应的理想抗原特异性方法，因为它是非侵入性的，不需要对患者细胞进行免疫抑制或基因操作。该提案利用了基于使用植物叶绿体作为高效生物反应器的独特概念，用于生产和口服递送治疗性蛋白抗原，无需发酵、纯化、冷链或无菌注射。生物封装的抗原在胃中受到保护，免受酸或酶的影响，但当植物细胞壁被共生细菌消化时，就会在肠道中释放。我们建议进一步推进这种方法，将抗原-配体融合物有效递送至肠道相关淋巴组织。我们还在开发适合临床转化的口服给药系统（基于可食用生菜）方面取得了实质性进展。 在X连锁出血性疾病血友病的治疗中，针对治疗性凝血因子的抑制性抗体的形成代表了一种严重的并发症，其大大增加了发病率和死亡率。例如，由于 IX 因子 (F.IX) 基因缺失或早期终止密码子而患有 B 型血友病的患者形成抑制剂的风险增加。大多数 F.IX 抑制剂不仅滴度高且难以消除，而且这些抗体通常与潜在危及生命的过敏反应有关。最近，我们证明，口服 F.IX（由烟草叶绿体产生并生物封装在植物细胞中）可防止血友病 B 的蛋白质替代疗法中抑制剂的形成和过敏反应（在 PNAS 107:7101 中介绍）。这些结果说明了我们针对遗传性蛋白质缺陷的免疫调节疗法的有效性。 该提案的目标是开发一种针对 B 型血友病的口服免疫调节方案，以预防或减轻致病性抗体反应（包括过敏反应）；剖析抗原呈递和免疫调节的潜在机制；寻找有效抗原递送的替代跨粘膜载体；测试针对具有相似抗体/过敏反应的不同疾病（溶酶体贮积症庞贝病）的方法；开发转质体生菜来表达 F.IX，用于未来人类口服给药；研究冻干转基因材料的稳定性和微生物污染；并在血友病 B 的大型动物模型中进行转化研究。我们假设我们的低成本方法可以预防性地用于多种疾病，例如血友病和溶酶体贮积症，从而消除免疫抑制的需要。